Our income is good, not astronomical. I work FT and my DH works PT on an hourly basis.
Here are some of the key ways that we scrimp for vacations
1) Rarely eating out. DH and I have "date night" once a month, and sometimes we've gone for burritos. They're yummy and the point is to be together. This includes when I take the kids to the pool and library for the day. We bring lunch from home along with us. In good weather we eat outside. In bad weather we eat at the food court at the mall. I rarely see other people doing this, and something I wonder if I'm not too strict. But the kids don't complain. They like the food DH packs for us. And these small things are what enable us to pay for the big things.
2) One, 12 year old car. DH drives it to work. I ride the bus (my employer pays busfare.)
3) No cellphones, no cable TV.
4) Thrift store clothing. Also, for DH and me, it's "use it up, wear it out, make it do or do without." I still wear clothes that I got 10, 15, 20 years ago. I don't wear any makeup. (I don't do this in order to save money, but I realize that going without makeup is cheaper than wearing makeup!)
5) We get books from the library.
6) No babysitting or after-school care costs. We swap with other families.
7) We often camp or stay with friends when travelling.
8) When giving gifts, we buy on sale and try to use creativity to substitute for money. Example, my SIL's brother is single, has a great job, is very generous to my nephew. We made nephew an ABC book using photos of our kids. Brother and SIL said it is the best gift nephew has ever gotten.
9) We use compact fluorescent light bulbs, are scrupulous about turning lights off, and we unplug things like the coffee maker that have a clock display, because they're always draining power. I use the dryer for 1 load of laundry and hang another load to dry. On days I go to the gym, I got first thing in the morning and take a shower there.
10) We clean our own house, mow our own lawn and take our own trash to the landfill. I do get professional hair cuts, but I cut the girls' hair and DH cuts his own.
I am very happy with our lifestyle. Our life is full of what we like and think is important-- time together, time with friends, time outdoors, reading, making things.